This invention relates to a combustion apparatus using a forced flue type burner, that is, a burner of such a type as to take in air necessary for combustion from outside of a room by means of a fan without discharging a flue gas to the inside of the room with a view of improving the room atmosphere or the sanitory conditions within the room, and is particularly used in a warm air generator, a drier, a boiler, etc.
More particularly, the present invention relates to a combustion apparatus provided with a slit-type flame nozzle and a throttled part in parallel to the flame nozzle in a combustion gas passage of the burner.